/// <summary>
/// Creates a <see cref="Stream"/> which can be used to access the given <see cref="TorrentFile"/>
/// while it is downloading. This stream is seekable and readable. The first and last pieces of
/// this file will be buffered before the stream is created if <paramref name="prebuffer"/> is
/// set to true. Finally, this stream must be disposed before another stream can be created.
/// </summary>
/// <param name="file">The file to open</param>
/// <param name="prebuffer">True if the first and last piece should be downloaded before the Stream is created.</param>
/// <param name="token">The cancellation token.</param>
/// <returns></returns>
public async Task <Stream> CreateStreamAsync(TorrentFile file, bool prebuffer, CancellationToken token)
{
if (file == null)
{
throw new ArgumentNullException(nameof(file));
}
if (!Manager.Torrent.Files.Contains(file))
{
throw new ArgumentException("The TorrentFile is not from this TorrentManager", nameof(file));
}
if (!Active)
{
throw new InvalidOperationException("You must call StartAsync before creating a stream.");
}
if (ActiveStream != null && !ActiveStream.Disposed)
{
throw new InvalidOperationException("You must Dispose the previous stream before creating a new one.");
}
Picker.SeekToPosition(file, 0);
ActiveStream = new LocalStream(Manager, file, Picker);
var tcs = CancellationTokenSource.CreateLinkedTokenSource(Cancellation.Token, token);
if (prebuffer)
{
ActiveStream.Seek(ActiveStream.Length - 1, SeekOrigin.Begin);
await ActiveStream.ReadAsync(new byte[1], 0, 1, tcs.Token);
ActiveStream.Seek(0, SeekOrigin.Begin);
await ActiveStream.ReadAsync(new byte[1], 0, 1, tcs.Token);
}
return(ActiveStream);
}
/// <summary>
/// Creates a <see cref="Stream"/> which can be used to access the given <see cref="TorrentFile"/>
/// while it is downloading. This stream is seekable and readable. The first and last pieces of
/// this file will be buffered before the stream is created if <paramref name="prebuffer"/> is
/// set to true. Finally, this stream must be disposed before another stream can be created.
/// </summary>
/// <param name="file">The file to open</param>
/// <param name="prebuffer">True if the first and last piece should be downloaded before the Stream is created.</param>
/// <param name="token">The cancellation token.</param>
/// <returns></returns>
public async Task <Stream> CreateStreamAsync(ITorrentFileInfo file, bool prebuffer, CancellationToken token)
{
if (file == null)
{
throw new ArgumentNullException(nameof(file));
}
if (Manager.Files == null)
{
throw new InvalidOperationException("The metadata for this torrent has not been downloaded. You must call WaitForMetadataAsync before creating a stream.");
}
if (Manager.State == TorrentState.Stopped || Manager.State == TorrentState.Stopping || Manager.State == TorrentState.Error)
{
throw new InvalidOperationException($"The torrent state was {Manager.State}. StreamProvider cannot be used unless the torrent manager has been successfully started.");
}
if (!Manager.Files.Contains(file))
{
throw new ArgumentException("The TorrentFile is not from this TorrentManager", nameof(file));
}
if (ActiveStream != null && !ActiveStream.Disposed)
{
throw new InvalidOperationException("You must Dispose the previous stream before creating a new one.");
}
ActiveStream = new LocalStream(Manager, file, PieceRequester);
var tcs = CancellationTokenSource.CreateLinkedTokenSource(Cancellation.Token, token);
if (prebuffer)
{
ActiveStream.Seek(ActiveStream.Length - Manager.PieceLength * 2, SeekOrigin.Begin);
await ActiveStream.ReadAsync(new byte[1], 0, 1, tcs.Token);
ActiveStream.Seek(0, SeekOrigin.Begin);
await ActiveStream.ReadAsync(new byte[1], 0, 1, tcs.Token);
}
ActiveStream.Seek(0, SeekOrigin.Begin);
return(ActiveStream);
}
